Re: /usr/local [was: CPPFLAGS prob]

[Russell Shaw]

Dan Kegel wrote:
> Russell Shaw wrote:
>
> > Dan Kegel wrote:
> >
> > > Paul Jarc wrote:
> > >
> > > > Dan Kegel <address@hidden> wrote:
> > > >
> > > > > The right thing to do is use 
> > > > > /opt/arm-linux/usr/lib/pkgconfig/audiofile.pc,
> > > > > which will point to the right library.
> > > >
> > > >
> > > > Right.  So set PKG_CONFIG_PATH=/opt/arm-linux/lib/pkgconfig.
> > >
> > >
> > > I certainly agree that'd do it.  Not sure that Russell does yet, though.
> >
> >
> > That is what i currently do.
>
>
> Well, I guess we were in violent agreement, then.
>
> One caveat, though: the manpage says
>        PKG_CONFIG_PATH
>               A  colon-separated  (on  Windows,  semicolon-separated)  
>               list of directories to search for .pc files.  The default 
>               directory will always be searched after searching the path;
>               the default is lib-dir/pkgconfig where libdir is the libdir
>               where pkg-config  was installed.
> What happens if you don't have the library in question installed
> in PKG_CONFIG_PATH?  pkg-config will silently search /usr/lib/pkgconfig,
> and possibly grab the wrong version of the library.

configure.ac checks the library via pkg-config, so regardless of what
library gets detected, if the autoconf check accepts the library version,
the resulting build should work.

> If you're
> unlucky, the library will link, but the resulting program won't run.
> One more little reason, perhaps, to have a separate copy of pkg-config
> per installed userland.

If autoconf doesn't complain, the result should work. It is up to the
user to make sure the right <package>.pc file is accessed by pkg-config.